2 OVERVIEW

The INS common Software provides a set of tools, libraries, rules, definitions and guidelines to support the development of VLT Instrumentation Software.

2.1 Format definitions

There are a number of file-, command- and parameter-formats and layouts to be defined for all instruments¹:

· The format of files related to Observation Blocks and Templates.

· The layout of the directory structure for instrument related files

Most of what refers to formats is subject to approval by the Data Interface Control Board, with the aim of using identical names/formats at the scope of ESO as a whole. This board will make all standardized formats publicly available.

2.2 Common subroutines and utilities

There are also a number of libraries and utilities available for all instruments:

· The Base ICS package (see [21]) provides the main functionality of standard ICS devices.

· The Base ICS GUI package (see [22]) provides support for the implementation of the ICS stand-alone GUI.

· The FIERA Software package (see [24]) is available for scientific optical detectors

· The IRACE Software package (see [25]) is available for scientific infrared detectors

· The CCD Software package (see [23]) is available for technical CCD systems

· The rtd package supports detector data display (see [32]).

· The transmission of detector data from LCU to IWS is provided with the module dxf (see [18]).

· A Protocol Converter, interfacing external (i.e. non-VLT) software, such as on-line MIDAS, is available with module pco (see [19]).

· The Base OS Stub package provides the core functionality of the OS Server and Archiver processes (see [26]).

· The Common Software for Templates (see [29]) provides support for Templates development.

· Facilities to monitor the amount of free disk space for detector data are available with module ist (see [20]).

· A tool to support the installation from scratch of a VLT Software package, such as an instrument, is provided with module pkgin (see [27]).

· A tool to support the handling of Instrument Configuration keywords and files is available in module ctoo (see [30]).

· A tool to support the start-up/shut-down of the whole Instrument Software or parts of it is available in module stoo (see [28]).

· A complete Instrument Software package, including test Software, called Template Instrument (see [31] and [33]) is available. It provides a wide range of examples. It is supposed to be the starting point for the implementation from scratch of the control Software for a new Instrument.

2.3 Standard Database structure

The structure of the On-Line Database for all Instruments is very similar. Furthermore, some common points and attributes are mandatory to support functionality available in the INS common software.

2.4 Standard states

As for any other VLT Software package also Instrument Software applications define a standard set of states and the related commands to switch from one state to another.

2.5 Standard commands

Apart from having a standard structure, all VLT instrumentation software will have a number of functions that are identical across the different instrument software packages, e.g. all instruments need to be set up, all detectors require a "start" and a "status" command. In other words, there are a number of commands that can have identical names and set of parameters, independent of the instrument; in the interest of all classes of users they must have.

Similarly an effort is made to align the INS command names with the LCU standard commands that provide the underlying functionality, and at the same time to differentiate names if the functionality is not identical. This is however not always possible or desirable (e.g. the status command).

Alias files and data compression, described in previous issues of this document, are not supported any more.